From OMIMCapillary malformation-arteriovenous malformation-1 (CMAVM1) is an autosomal dominant disorder characterized by atypical capillary malformations (CMs), often in association with fast-flow vascular malformations, including arteriovenous malformations (AVMs) and arteriovenous fistulas (AVFs), and Parkes Weber syndrome (PKWS). The CMs are usually multifocal and are surrounded by a pale halo with a central red dot; they increase in number with age. The AVMs generally occur in the brain or on the face or extremities. Intracranial AVMs include vein of Galen aneurysmal malformations (VGAMs). Parkes Weber syndrome is a specific type of CMAVM that presents with limb overgrowth, more commonly affecting one of the lower extremities (Eerola et al., 2003; Revencu et al., 2013; Johnson and Navarro, 2017). Parkes Weber syndrome is characterized by a cutaneous blush with underlying multiple micro-AVFs in association with soft-tissue and skeletal hypertrophy of the affected limb (Mulliken and Young, 1988).
Genetic Heterogeneity of Capillary Malformation-Arteriovenous Malformation
Also see CMAVM2 (618196), caused by mutation in the EPHB4 gene on chromosome 7q22.
http://www.omim.org/entry/608354 From MedlinePlus GeneticsCapillary malformation-arteriovenous malformation syndrome (CM-AVM) is a disorder of the vascular system, which is the body's complex network of blood vessels. The vascular system consists of arteries, which carry oxygen-rich blood from the heart to the body's various organs and tissues; veins, which carry blood back to the heart; and capillaries, which are tiny blood vessels that connect arteries and veins.
CM-AVM is characterized by capillary malformations (CMs), which are composed of enlarged capillaries that increase blood flow near the surface of the skin. These malformations look like multiple small, round, pink or red spots on the skin. In most affected individuals, capillary malformations occur on the face, arms, and legs. These spots may be visible from birth or may develop during childhood. By themselves, capillary malformations usually do not cause any health problems.
In some people with CM-AVM, capillary malformations are the only sign of the disorder. However, other affected individuals also have more serious vascular abnormalities known as arteriovenous malformations (AVMs) and arteriovenous fistulas (AVFs). AVMs and AVFs are abnormal connections between arteries, veins, and capillaries that affect blood circulation. Depending on where they occur in the body, these abnormalities can be associated with complications including abnormal bleeding, migraine headaches, seizures, and heart failure. In some cases the complications can be life-threatening. In people with CM-AVM, complications of AVMs and AVFs tend to appear in infancy or early childhood; however, some of these vascular abnormalities never cause any symptoms.
Some vascular abnormalities seen in CM-AVM are similar to those that occur in a condition called Parkes Weber syndrome. In addition to vascular abnormalities, Parkes Weber syndrome usually involves overgrowth of one limb. CM-AVM and some cases of Parkes Weber syndrome have the same genetic cause.
https://medlineplus.gov/genetics/condition/capillary-malformation-arteriovenous-malformation-syndrome